Formed as 2 Wessex Brigade Royal Field Artillery (TF) in February 1920. It became 55 (Wessex) Brigade Royal Field Artillery (TA) in 1921. In June 1924 it was re-designated as 55 (Wessex) Field Brigade Royal Artillery (TA). Another change in title came in April 1927. The Brigade was re-named as 55 (Wessex) Army Field Brigade RA (TA). The Regiment was re-designated 55 (Wessex) Field Regiment RA (TA) from 55 Army (Wessex) Field Brigade in November 1938 on a two battery basis. 217 and 220 Batteries both went to 112 Field Regiment. A third battery was raised in November 1940. 55 (Wessex) Field Regiment RA (TA) was placed in suspended animation in December 1946 and reconstituted in January 1947 as 255 (Wessex) Medium Regiment RA (TA).
Illustrations of the formation badges under which a unit served or supported are given. This is no guarantee that the unit used this formations badge.
| 3 Sep 39 |  |
45 Infantry Division | Taunton, Somerset, UK |
| Jun 42 |  |
Guards Armoured Division | UK |
| Jun 44 | |
Guards Armoured Division | N W Europe |
| Jun 45 | Guards Division | N W Europe |
Batteries
| 1921 | 217, 218, 219, 220 |
| Sep 27 | 217, 220, 373, 374 – 217 & 219 Batteries amalgamated to form 219 Battery. 219 & 218 Batteries to 95 Field Brigade. 217 Battery re-formed |
| Nov 38 | 373 (West Somerset Yeomanry), 374 (West Somerset Yeomanry) |
| Nov 40 | 373, 374, 439 |
Equipment
| 1944 | 25 pdr, Sherman Observation Post tanks |